Wikipedia is a free online encyclopedia in which anyone can write and edit articles. It is often updated very quickly. Because anyone can write or edit an article, information may be incorrect, biased, or out of date. Yet because articles are constantly reviewed and updated, inaccuracies are swiftly identified and corrected.
Interesting note - In 2004, a journalist invited people to add mistakes to the Wikipedia entry on the city of Syracuse to see how long it took to fix. All the mistakes were corrected within hours. While this showed Wikipedia’s self healing abilities, even from deliberate vandalism, for those hours Wikipedia was incorrect. (Criticism of Wikipedia, 2009)
Also, a 2005 report in Nature found that there was little to choose between the accuracy of information in Wikipedia and Encyclopedia Britannica when they compared articles on the same scientific topics. (Giles, 2005)
Pros
Freely available.
Some entries can be the most up-to-date available, especially on more esoteric or obscure issues.
There is a history of discussion on some topics which allows you to see how contributors arrive at particular points of view.
May have useful references to follow up.
Cons
Anyone con contribute, whether an expert or not.
Can be heavily biased.
Can be of substandard quality, subject to misinformation and error.
Articles can be the target of deliberate misrepresentation or "vandalism"
References
Criticism of Wikipedia. (2009, November 30). Wikipedia. http://en.wikipedia.org/wiki/Wikipedia:Criticisms.
Giles, J. (2005). Internet encyclopedias go head to head. Nature, 438, 900-901. doi:10.1038/438900.
Why use a library database rather than Google? Databases from WKU Libraries are more likely to provide you with relevant information of a scholarly nature that is appropriate to University level research projects.
Library databases . . .
Generally contain high-quality information
Contain peer-reviewed articles
Contain articles by known authors
Contain scholarly information
Are subject-specific
Support refined searching
The free Web . . .
Is not quality controlled
Is rarely peer-reviewed
Doesn't always list authors' names
Contains a mixture of specialized and popular (non- specialized) information
Has limited search capabilities